Author Topic: Warning - Wheel bearing bolts fallen out and loose from brake heat (Read 12556 times)

kennysabarese · « **on:** July 04, 2012, 10:31:51 PM »

So when my calipers were being replaced they noticed that my front right hub had lost a bearing bolt and the others were lose and on the left side some had come loose. We are talking so lose you could turn with your fingers.

They could only imagine this was caused by excessive heat from racing.

Be warned.

Also replacement bolts are hard to find from a dealer, but are standard so you can get them from other places.

Torque to 85 ft lbs

idkfa · « **Reply #1 on:** July 05, 2012, 08:46:00 AM »

I thought this used to be stickied over at the other board but it's definitely something that should be part of every racer's inspection:
http://www.solsticeforum.com/forum/f48/axers-racers-very-important-check-hub-bolts-if-driven-hard-35030/

While mine was loose (only one bolt left) I actually lost brakes. Kinda wild.

TomatoSoup · « **Reply #2 on:** July 05, 2012, 08:54:29 AM »

I assume you mean item 12 in the diagram below. If so, for reference, the GM part# is 11570091 List: $6.44

BOLT. Rear Axle Shaft Bearing. Steering Knuckle Spindle. Wheel Brake Cylinder/Caliper.
(M12X1.75X43,24 THD,21.5 OD,10.9 STL)(08.900). Required: 03

[attachimg=1]

Critterman · « **Reply #3 on:** July 05, 2012, 09:13:07 AM »

There are 3 per hub correct?

idkfa · « **Reply #4 on:** July 05, 2012, 09:31:56 AM »

Quote from: TomatoSoup on July 05, 2012, 08:54:29 AM

I assume you mean item 12 in the diagram below. If so, for reference, the GM part# is 11570091 List: $6.44

BOLT. Rear Axle Shaft Bearing. Steering Knuckle Spindle. Wheel Brake Cylinder/Caliper.
(M12X1.75X43,24 THD,21.5 OD,10.9 STL)(08.900). Required: 03

[attachimg=1]

Quote from: Critterman on July 05, 2012, 09:13:07 AM

There are 3 per hub correct?

Yes and yes. Though I thought they came in packs of three (I don't usually order spares and I have a couple left over).

kennysabarese · « **Reply #5 on:** July 05, 2012, 10:02:14 AM »

In my case I'm talking about the FRONT. my rears were fine. they just happened to notice the wheels shook when they lifted the car.

idkfa · « **Reply #6 on:** July 05, 2012, 10:09:05 AM »

I missed that, most every reference to this problem is on the front.

kennysabarese · « **Reply #7 on:** July 05, 2012, 10:18:31 AM »

Yeah, mine were put back with red locktite

idkfa · « **Reply #8 on:** July 05, 2012, 10:28:04 AM »

I believe it's also the same part number that TS listed. I can't find any information on the hub procedure in my shop manual but I might not be looking in the right documents.

In the other thread there was some conversation with GM and their recommendation was the same, red locktite. There was also a suggestion to mark the bolts and the hub to see if there's been any movement as well as to be careful about over-torquing (had been a while since I read that thread).

kennysabarese · « **Reply #9 on:** July 05, 2012, 10:29:54 AM »

Yeah the bolts are the same front and rear. FYI I added the service manual torque to the top post. 85 ft lbs

Sol Asylum · « **Reply #10 on:** July 05, 2012, 01:32:50 PM »

A word of caution though about loctite, the way you remove a fastener that loctite was used on is to apply heat which is what your brakes are going to do. If I was racing my car and had this issue I would probably be getting some drilled head bolts and safetywire them.

TomatoSoup · « **Reply #11 on:** July 05, 2012, 01:41:17 PM »

Quote from: idkfa on July 05, 2012, 09:31:56 AM

Yes and yes. Though I thought they came in packs of three (I don't usually order spares and I have a couple left over).

The listing I quoted, says "Reqd 03" which I assumes means they're sold individually.

kennysabarese · « **Reply #12 on:** July 05, 2012, 06:20:45 PM »

Quote from: Sol Asylum on July 05, 2012, 01:32:50 PM

A word of caution though about loctite, the way you remove a fastener that loctite was used on is to apply heat which is what your brakes are going to do. If I was racing my car and had this issue I would probably be getting some drilled head bolts and safetywire them.

How much heat do you apply to loosen it?

The safety wire is just to prevent from losing it? Or does it keep the bolt tight?

Go-N Def · « **Reply #13 on:** July 05, 2012, 06:33:23 PM »

Quote from: Kenny on July 05, 2012, 06:20:45 PM

How much heat do you apply to loosen it?

The safety wire is just to prevent from losing it? Or does it keep the bolt tight?

You could always just drive it for a bit and then quickly put it in the air and remove them. Otherwise, you'd need a heat gun on high pointed at it for quite a while.

The safety wire keeps them from rotating.

kennysabarese · « **Reply #14 on:** July 05, 2012, 06:35:08 PM »

Ah cool yeah I see how it works

Gentleman Jack · « **Reply #15 on:** July 05, 2012, 07:42:57 PM »

Kenny,

are you going to be racing anymore? I would think the loctite is just fine for the street. The safety wire is probably good if you are going to continue racing.

Sol Asylum · « **Reply #16 on:** July 05, 2012, 09:32:58 PM »

Each loctite has it's own temp range so you would need to look up how much heat it takes for it to fail. Like GND said a heat gun will work or I have even used a propane torch. I wouldn't be a bit surprised to find the brake heat exceeds most loctite's temp range.

The safety wire is routed between the bolts such that if one bolt were to pull in a loosening direction it will be pulling the other bolt tighter which it supposed to keep the bolts from rotating at all.

kennysabarese · « **Reply #17 on:** July 05, 2012, 10:21:27 PM »

Dunno if I am going to race again. 500 degrees for red locktite.

Critterman · « **Reply #18 on:** July 06, 2012, 09:56:14 AM »

Did you have your temp gun when you were racing? I'm thinking they get hotter than that.

kennysabarese · « **Reply #19 on:** July 06, 2012, 10:03:01 AM »

Each component is a different heat. Calipers are much cooler than rotors for example. I don't have my temps recorded from the track unfortunately. But I think I remember rotors around 1,000F. But the bearing bolts certainly isn't as hot as the rotors as there is a bunch of metal from the other components in between.

rlhammon · « **Reply #20 on:** August 26, 2012, 09:48:18 PM »

I've used blue Loctite on my hub bolts (front and rear) for autocrossing since I found one loose (and the thread on the other board went up). You can remove "blue" without added heat, and they seem to hold just fine for a full season at least (I usually pull the corners off the car each winter for some sort of work and reapply Loctite on install).

I know my rotors glow red and throw sparks with the Carbotech pads on them... can't imagine Kenny is getting any more heat than I am, as he's getting a lot more cooling than I am as well.

I don't see how you can use wire. The bolts don't come through the hub far enough to tap a hole and route wire through... and you don't have clearance to run a longer bolt to give you the access you need for wire anyway.

snaponbob · « **Reply #21 on:** August 26, 2012, 11:54:58 PM »

Quote from: rlhammon on August 26, 2012, 09:48:18 PM

I've used blue Loctite on my hub bolts (front and rear) for autocrossing since I found one loose (and the thread on the other board went up). You can remove "blue" without added heat, and they seem to hold just fine for a full season at least (I usually pull the corners off the car each winter for some sort of work and reapply Loctite on install).

I know my rotors glow red and throw sparks with the Carbotech pads on them... can't imagine Kenny is getting any more heat than I am, as he's getting a lot more cooling than I am as well.

I don't see how you can use wire. The bolts don't come through the hub far enough to tap a hole and route wire through... and you don't have clearance to run a longer bolt to give you the access you need for wire anyway.

Never had a hub bolt come loose ..... yet. But SPARKS ?!?!?!?! Really?

Carbon Sky · « **Reply #22 on:** August 27, 2012, 12:03:30 AM »

Quote from: snaponbob on August 26, 2012, 11:54:58 PM

Never had a hub bolt come loose ..... yet. But SPARKS ?!?!?!?! Really?

If they are metallic pads yah. Happened to me on a set of some metallic pads I have run before.

elff · « **Reply #23 on:** August 27, 2012, 11:14:31 AM »

Yup

Dave@DDM can verify my fronts do that

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Author Topic: Warning - Wheel bearing bolts fallen out and loose from brake heat (Read 12556 times)